If you are logged in as a WHMCS administrator and viewing a client’s account (using the “Login as Client” option) or have manually logged into a client’s account while also being logged in as a WHMCS administrator, you will not receive any prompts or requests to allow for notifications.

In order to receive client notification requests, you must log out of the WHMCS administrator area and login directly as the client. If you still do not receive any requests, please check the browser’s “Developer Console” for any errors or visit the “Browser Notifications” page directly by clicking the “Browser Notifications” link in the WHMCS shortcut menu.

The requirements are listed below. The module may work under different conditions, but has only been tested by our developers in these scenarios. This article assumes that your system, server and PHP installation meets the requirements of WHMCS itself. Their requirements can be found here https://docs.whmcs.com/System_Requirements

System Requirements

Clear understanding of using WHMCS as well as uploading, installing and configuring addons and gateways